The present invention relates to a seat-belt guide anchor that is supported on a vehicle body, for example, a pillar, and swings freely. The guide anchor guides a seat belt of a seat belt device, in which the seat belt slides through the anchor in a longitudinal direction thereof.
A seat belt device attached to a seat of a vehicle protects a passenger from injury due to a collision with a vehicle body or the like by restraining the passenger with a seat belt in the case of an emergency such as a vehicle collision.
Such a seat belt device is provided with a guide anchor that is supported on an inner wall of a vehicle body, for example, a pillar, and that has a belt guide hole for guiding the seat belt in a longitudinal direction thereof. In this case, in general, when the guide anchor is mounted on the vehicle body, the belt guide hole extends in forward and backward directions of the vehicle. The guide anchor allows the seat belt to restrain the passenger in a correct position.
In the guide anchor for the seat belt, when the seat belt is extracted at a relatively higher speed than a usual belt-extraction speed, for example, upon wearing the belt, it is sometimes biased to a front side end of the belt guide hole in a vehicle, as shown in FIG. 12. When the seat belt is biased to the vehicle""s front side end of the belt guide hole, it does not smoothly slide through the belt guide hole, and moreover, sometimes it becomes troublesome to restore the seat belt.
Accordingly, in Japanese Utility Model Application No. 03-96565 (Japanese Utility Model Publication (KOKAI) No. 05-44719), hereinafter referred to as a xe2x80x9cpublicationxe2x80x9d, it is disclosed that a guide anchor prevents a seat belt from being biased to one end of a belt guide hole. In the guide anchor disclosed in the publication, projections or recesses for preventing the bias of the seat belt are formed in a portion where the seat belt slides so that they are oriented in a traveling direction of the seat belt. The seat belt is prevented from being biased by the friction between these projections or recesses and the seat belt.
In the past, various types of seat belt devices have been developed in which, in the case of an emergency, such as a vehicle collision, a pretensioner is actuated to drive a retractor in a seat-belt winding direction, thereby winding the seat belt and increasing a restraining force of the seat belt for the passenger. Since the retractor rapidly winds the seat belt in response to the actuation of the pretensioner in such a seat belt device, the above-described bias problem can occur. Accordingly, it is possible to prevent the seat belt from being biased upon the actuation of the pretensioner by using the guide anchor disclosed in the above publication.
However, when the pretensioner is actuated, the seat belt is wound far more rapidly than in a situation disclosed in the above publication. For this reason, it is difficult to effectively prevent the seat belt from being biased with the projections or recesses oriented in the seat-belt traveling direction as disclosed in the above publication. Even when the guide anchor in the publication is used, the seat belt still may be biased.
Further, other types of seat belt devices have been developed in which an impact of a seat belt applied to the passenger and a load on the seat belt are reduced by an energy absorption mechanism (hereinafter also referred to as an xe2x80x9cEA mechanismxe2x80x9d) that absorbs an impact energy to the seat belt when a retractor locks the withdrawal of the seat belt in the case of an emergency, such as a vehicle collision. The EA mechanism absorbs the impact energy by twisting a torsion bar provided in the retractor. In this case, the seat belt is drawn from the retractor by an amount corresponding to the torsion bar twist.
When the seat belt is drawn upon the EA mechanism being actuated, since it is drawn far more rapidly than in a normal operation, the above-described bias of the seat belt may occur. Accordingly, it is considered to use the guide anchor disclosed in the above publication to prevent the seat belt from being biased, in a manner similar to that in the above case in which the pretensioner is actuated.
However, since the seat belt is extracted far more rapidly than in a situation in the above publication when the EA mechanism is actuated, it is similarly difficult to effectively prevent the bias of the seat belt with the projections or recesses disclosed in the above publication.
As described above, it is difficult to effectively prevent the seat belt bias with the guide anchor disclosed in the above publication when the seat belt is rapidly extracted and is rapidly retracted in the case of an emergency, such as a vehicle collision.
The present invention has been made in view of such circumstances, and an object of the invention is to provide a seat-belt guide anchor that can more effectively and reliably prevent a seat belt from being biased when the seat belt is rapidly drawn and wound in the case of an emergency, such as a vehicle collision.
Further objects and advantages of the invention will be apparent from the following disclosure of the invention.
In order to solve the above problems, the first aspect of the invention provides a seat-belt guide anchor that is supported on a vehicle body, such as a pillar, and swings freely. The seat-belt guide anchor guides a seat belt while the seat belt travels through a belt guide hole so as to slide in a longitudinal direction thereof. A projection or a recess is formed in a sliding portion for the seat belt. A vehicle-rear side end of the projection or a vehicle-rear side end of the sliding portion forming the recess is inclined with respect to a direction perpendicular to the belt guide hole disposed in the sliding portion for the seat belt in a state in which the seat-belt guide anchor is mounted on the vehicle body. An angle of the inclination is set to be more than an inclination angle of a traveling direction of the seat belt through the belt guide hole with respect to the orthogonal direction.
The second aspect of the invention provides a seat-belt guide anchor that is supported on a vehicle body, such as a pillar, and swings freely. The seat-belt guide anchor guides a seat belt while the seat belt travels through a belt guide hole so as to slide in a longitudinal direction thereof. A projection or a recess is formed in a sliding portion for the seat belt. A vehicle-rear side end of the projection or a vehicle-rear side end of the sliding portion forming the recess is inclined with respect to a direction perpendicular to the belt guide hole disposed in the sliding portion for the seat belt in a state in which the seat-belt guide anchor is mounted on the vehicle body. An angle of the inclination is set to be smaller than an inclination angle of a traveling direction of the seat belt through the belt guide hole with respect to the orthogonal direction, or opposite with respect to the orthogonal direction.
Further, in the third aspect of the invention, a projection is formed in a rib shape, and a recess is formed in a concave groove shape.
The fourth aspect of the invention provides a seat-belt guide anchor that is supported on a vehicle body, such as a pillar, and swings freely. The seat-belt guide anchor guides a seat belt while the seat belt travels through a belt guide hole so as to slide in a longitudinal direction thereof. A plurality of projections or recesses is formed in a sliding portion for the seat belt. Vehicle-rear side ends of the projections or vehicle-rear side ends of the recesses include the first vehicle-rear side end and the second vehicle-rear side end in a state in which the seat-belt guide anchor is mounted on the vehicle body. The first vehicle-rear side end is inclined with respect to a direction perpendicular to the belt guide hole disposed in the sliding portion for the seat belt. An angle of the inclination is set to be more than an inclination angle of a traveling direction of the seat belt through the belt guide hole with respect to the orthogonal direction. The second vehicle-rear side end is inclined with respect to a direction perpendicular to the belt guide hole disposed in the sliding portion for the seat belt, and the angle of the inclination is set to be less than the inclination angle of the traveling direction of the seat belt through the belt guide hole with respect to the orthogonal direction, or opposite to the orthogonal direction.
In the fifth aspect of the invention, the vehicle-rear side end of the projection or the vehicle-rear side end of the sliding portion forming the recess is formed of a round portion having a small diameter or of an edge portion.
Further, in the sixth aspect of the invention, the vehicle-front side end of the projection or the vehicle-front side end of the sliding portion forming the recess is formed of a round portion having a large diameter or of a chamfered portion.
In the seventh aspect of the invention, the vehicle-front side end of the projection or the vehicle-front side end of the sliding portion forming the recess extends in the traveling direction of the seat belt through the belt guide hole.
Further, in the eighth aspect of the invention, the vehicle-front side end of the projection or the vehicle-front side end of the sliding portion forming the recess is formed in a stepped shape. The stepped portion is formed of predetermined combinations of the first vehicle-front side end portions parallel to the traveling direction of the seat belt through the belt guide hole, and the second vehicle-front side end portions perpendicular to the first vehicle-front side end portions.
In the first aspect of the invention, when the seat belt is rapidly wound, for example, in response to the pretensioner in the case of an emergency such as a vehicle collision, the seat belt is restrained from moving toward the vehicle front side by the vehicle-rear side projection end or the vehicle-rear side end of the seat-belt sliding portion forming the recess. This makes it possible to more effectively and reliably prevent the seat belt from being biased toward the vehicle front side. The seat-belt guide anchor is particularly suitable for the seat belt device having the pretensioner.
In the second aspect of the invention, when the seat belt is drawn while absorbing the impact energy, for example, in response to the EA mechanism in the case of an emergency such as a vehicle collision, the seat belt is restrained from moving toward the vehicle front side by the vehicle-rear side projection end or the vehicle-rear side end of the seat-belt sliding portion forming the recess. This makes it possible to more effectively and reliably prevent the seat belt from being biased toward the vehicle front side. The seat-belt guide anchor is particularly suitable for the seat belt device without the pretensioner, but with the EA mechanism.
Further, in the third aspect of the invention, since the projection is formed in the rib shape and the recess is formed in the concave groove shape, the structure is simplified to facilitate production.
In the fourth aspect of the invention, when the seat belt is rapidly wound, for example, in response to the pretensioner in the case of an emergency such as a vehicle collision, the seat belt is restrained from moving toward the vehicle front side by the first vehicle-rear side projection ends or the first vehicle-rear side ends of the seat-belt sliding portion forming the recesses. Furthermore, when the seat belt is drawn while absorbing the impact energy, for example, in response to the EA mechanism in the case of an emergency such as a vehicle collision, the seat belt is restrained from moving toward the vehicle front side by the second vehicle-rear side projection ends or the second vehicle-rear side ends of the seat-belt sliding portion forming the recesses. This makes it possible to more effectively and reliably prevent the seat belt from being biased toward the vehicle front side. The seat-belt guide anchor is particularly suitable for the seat belt device with at least one of the pretensioner and the EA mechanism.
In the fifth aspect of the invention, since the vehicle-rear side end of the projection or the vehicle-rear side end of the sliding portion forming the recess is formed of the round portion having the small diameter and the edge portion, the seat belt is inhibited more effectively from moving toward the vehicle front side by the frictional reactive force between the vehicle-rear side end and the seat belt produced from the vehicle-rear side end.
In the sixth aspect of the invention, since the vehicle-front side end of the projection or the vehicle-front side end of the sliding portion forming the recess is formed of the round portion having the large diameter or the chamfered portion, little friction occurs between the vehicle-front side end and the seat belt, and the seat belt is inhibited from moving toward the vehicle front side due to the vehicle-front side end.
In the seventh aspect of the invention, since the vehicle-front side end of the projection or the vehicle-front side end of the sliding portion forming the recess extends in the traveling direction of the seat belt through the belt guide hole, little friction occurs between the vehicle-front side end and the seat belt, and the seat belt is inhibited from moving toward the vehicle front side due to the vehicle-front side end.
In the eighth aspect of the invention, since the vehicle-front side projection end or the vehicle-front side end of the sliding portion forming the recess is formed in the stepped shape by predetermined combinations of the first vehicle-front side end portions parallel to the traveling direction of the seat belt through the belt guide hole and the second vehicle-front side end portions perpendicular to the first vehicle-front side end portions, a force for moving the seat belt toward the vehicle front side is not produced by the vehicle-front side end. Therefore, when the seat belt is drawn, the turning of the guide anchor is inhibited, and the movement of the seat belt toward the vehicle front side is inhibited.